1. Field of the Invention
The present invention relates to a display device that is capable of shifting display contents having different colors and an overlapped part thereof.
2. Description of the Related Art
A display device of this kind is disclosed in Japanese patent laying-open publication No. 2001-100679. This display device has a first printed area part through which only blue light can pass and a second printed area part through which only green light can pass, the other printed area part to form a lightproof background, and a non-printed area part through which the blue light and the green light can pass. The first, second printed area parts and the other printed area part are formed by printing on a rear surface of a transparent sheet, which can be illuminated from a rear side thereof selectively by a first light source for emitting the blue light and a second light source for emitting the green light. When the first light source emits the blue light, it pass through the first printed area part and the non-printed area part, being cut off at the second printed area part and other printed area part, to form first display contents. When the second light source emits the green light, it pass through the second printed area part and the non-printed area part, being cut off at the first printed area part and other printed area part, to form second display contents. The non-printed area part correspond to an overlapping part of the first display contents and the second display contents.
The above known conventional display device, however, encounters a problem in that kinds of colors to display the display contents are limited by wavelength characteristics of two color films, that is the first and second printed area parts. This decreases freedom of choice in selecting color of display contents, for example, display contents displayed in white being unobtainable.
It is, therefore, an object of the present invention to provide a display device which overcomes the foregoing drawbacks and can extend a limitation due to the wavelength characteristics of a color film of a filter and obtain more colors for displaying display contents.